具有多个 WHERE 的 MYSQL 查询

Question

我有一个非常大的数据库。我需要运行查询以通过电子邮件和 load_date(日期/时间戳字段)进行搜索。我需要从 3 个不同的日期提取 3 个电子邮件用户。

所以我需要一个表来显示电子邮件(电子邮件字段):

email1@host.com
nextemail@site.com
finalemail.yosite.com

对于日期(load_date 字段):

2014-08-01
2014-08-06
2014-08-09

如果我运行这个:

SELECT email, load_date
  FROM table1
  WHERE email = 'email1@host.com' or email = 'nextemail@site.com' or email = 'finalemail.yosite.com

结果正确。

如果我运行:

SELECT email, load_date
  FROM table1
  WHERE load_date LIKE "2014-08-01%" or load_date LIKE "2014-08-06%" or load_date LIKE "2014-08-09%"

结果正确。

但是如果我把它们结合起来:

SELECT email, load_date
  FROM table1
  WHERE email = 'email1@host.com' or email = 'nextemail@site.com' or email = 'finalemail.yosite.com'
  and
   load_date LIKE "2014-08-01%" or load_date LIKE "2014-08-6%" or load_date LIKE "2014-08-09%"

我得到了一切!？

我做错了什么？？

Answer 1

AND 函数的优先级高于 OR 函数。您需要将您的 OR 封装在括号中。

SELECT email, load_date
FROM table1
WHERE (email = 'email1@host.com' or email = 'nextemail@site.com' or email = 'finalemail.yosite.com')
and (load_date LIKE "2014-08-01%" or load_date LIKE "2014-08-6%" or load_date LIKE "2014-08-09%")